The process of splitting a masonry block to create a rock-like appearance on the exposed face of the block is known. See, for example, Besser, U.S. Pat. No. 1,534,353, which discloses the manual splitting of blocks using a hammer and chisel. Automated equipment to split block is well-known, and generally includes a splitting table comprising a supporting table and one or more hydraulically-actuated splitting blades. These machines are useful for the high-speed processing of blocks. They produce a rock-face finish on the blocks. The edges of the faces are generally well-defined, i.e., “sharp”.
It is sometimes desirable to produce a concrete product that has edges which appear to be weathered. This has been a desired look for concrete pavingstones for sometime. Recently, it has become desirable to create the weathered look on the decorative face of concrete retaining wall blocks. The common process for producing the weathered look on pavers is to “tumble” the pavers in a rotary drum to knock off their sharp edges. This process can be used with some retaining wall blocks, as well, provided that the blocks do not have any features, such as integral concrete locator flanges, that would be damaged by the tumbling process. Tumbling is not an option with such blocks. The problem with the tumbling process is that it is costly. The process requires the capital investment in a tumbling apparatus, and the upkeep of that equipment. In addition, the pavers or blocks must be removed from the production line, tumbled, and then reassembled into suitable cubes for transportation. This makes the process labor-intensive.
Another option is to use a hammermill to attack the face of the block with various hammers. This option can slow down production, if it is done “in line”, because the process can only move as fast as the hammermill can operate on each block, and the block may need to be manipulated-flipped over and or rotated-to attack all of its edges.
Accordingly, there is a need for equipment and a process that will create the appearance of weathered edges on retaining wall blocks, in such a manner that it will not slow down the production line, will not add costly equipment to the line, will not be labor-intensive, and will not have high cull rates when processing blocks with integral locator flanges or other similar features.